Many types of merchandise are sold in automatic vending machines which use different types of dispensing mechanisms. FIG. 1 is a partial sectional view of one type of vending machine 1 which is suitable for storing and dispensing, for example, paper packages of beverages.
Storage chamber S is defined in vending machine 1, and at least one column C is disposed in storage chamber S to store merchandise. Column C includes outer frame 2 with merchandise discharge opening 2a, a plurality of shelves 3 extending backwardly within frame 2, and dispensing mechanism 4 located on the lower portion of frame 2 opposite discharge opening 2a. Dispensing mechanism 4 dispenses merchandise individually through discharge opening 2a. Each shelf 3 is vertically movably connectable with each other. When the merchandise stored on one shelf is sold out, the adjacent shelf 3 vertically translates and replaces the empty shelf.
Dispensing mechanism 4 includes merchandise conveying or pushing device 41 having a pair of pushing elements 411 horizontally movable along shelf 3 by motor 42 through endless chain elements 43, 44. Fall preventing device 45 which operates as a discharge control mechanism prevents the merchandise from falling into discharge opening 2a. Fall preventing device 45 is disposed on discharge opening 2a of column C and, as shown in FIG. 2, includes attachment element 451 fixed on outer frame 2, control plate 452 rotatably supported on attachment element 451 through support shaft 453, and coil spring 454 which biases control plate 452 toward merchandise A. Therefore, merchandise stored on the lowermost shelf 3 is normally held between control plate 452 and pushing element 411, and is dispensed by the movement of pushing element 411.
As explained above, the merchandise positioned for dispensing is held between control plate 452 of fall preventing device 45 and pushing element 411. The merchandise is normally pushed away from the discharge passage and are held in position due to the recoil strength of coil spring 454 on control plate 452. However, if the force of control plate 452 acting against merchandise A is small, merchandise A may fall through discharge opening 2a into the discharge passage of vending machine 1 when vending machine 1 is shaken, hit, or tilted. If the force of control plate 452 is strong, this problem is eliminated. However, if the recoil strength of coil spring 454 is increased, the dispensing force of pushing element 411 must be increased correspondingly to dispense merchandise. If the force of pushing element 411 is too strong, more than one unit of merchandise may be dispensed in one dispensing cycle.
Furthermore, control plate 452 is always unlocked and is rotated easily by external forces. Thus, merchandise may be stolen by pivoting control plate 452 from outside vending machine 1 through merchandise discharge opening 2a.